| 摘要 |
PROBLEM TO BE SOLVED: To prevent the cloudiness or damage of a read window, to prolong the service life of the read window and to improve workability in the case of exchanging the read windows by protruding a bank part in the vertical direction from a window surface toward an outward position of a window part so that a read medium becomes in noncontact with the window surface of the window part. SOLUTION: An image sensor 1 is constituted of a guide block 2 and a casing 3. The guide block 2 is detachably fixed to the casing 3 with a screw. An upper surface of the guide block 2 has a step structure (a height) composed of a flat surface and a back part 13. The bank part 13 is formed in a comb- teeth shape in an outward direction with a window part 14 as a center. Also, an edge part face 19 of this bank part 13 is finished on a slope having a specified inclination in the vertical direction. Since due to the height (h) of the bank part 13, a distance from the window part 14 to a read medium 12 is kept constant and reading is made possible without the read medium 12 directly touching the window part 14, the cloudiness or damage of the surface of the window part can be prevented. |
